Process and apparatus for producing a photographic print

Abstract

For the production of a photographic print of an original present in electronic format, optical representations (D) are produced from sequentially changing strip-shaped portions of the original by way of an electro optical, pixel wise operating converter device (3) and these optical representations (D) are projected onto a strip-shaped exposure region (E) on the copy material (P), whereby the strip-shaped exposure region (E) and the copy material (P) are moved relative to one another and at an essentially constant speed in a direction transverse to the longitudinal extent of the strip-shaped exposure regions (E), so that successively the image information of the whole original is exposed onto the total available surface of the copy material (P). Each strip-shaped portion of the original is thereby divided into at least two strip-shaped sections positioned one behind the other in longitudinal direction of the portion, separate optical representations are produced from the sections by way of the electro optical converter device (3) and these separate optical representations of the sections are projected onto the copy material (P) in at least two strip-shaped partial exposure regions (E1, E2) which are positioned one behind the other in longitudinal direction and together form the strip-shaped exposure region (E). A digital micro mirror field is preferably used as the electro optical converter device (3). In this manner, large format photographic prints of high quality can be produced with relatively low constructive cost by using conventional converter devices.

What is claimed is: 
     
       1. System for producing a photographic print of an original in electronic format by strip wise projection of image information of the original onto a photographic copy material, said system including an apparatus comprising: a memory for the storage of said image information of the original;   an electro optical pixel-wise operating converter device;   a control associated with said electro optical converter device for producing optical representations of strip-shaped portions of the original stored in the memory;   a projection optics for projecting the optical representations of the strip-shaped portions onto a strip-shaped exposure region of the copy material; and   drive means for shifting the strip-shaped exposure region along the copy material at a constant speed and in a direction transverse to a longitudinal extent of the strip-shaped exposure region, the control dividing each strip-shaped portion of the stored original into at least two longitudinal strip-shaped sections for producing separate optical representations by the electro optical converter device, the projection optics projecting said separate optical representations of the sections onto the copy material in at least two longitudinal strip-shaped partial exposure regions which form the strip-shaped exposure region, wherein the system produces the photographic print original onto the copy material by:   sequentially producing, by the electro optical, pixel-wise operating converter device, optical representations of the different strip-shaped portions of the original;   exposing said optical representations onto a strip-shaped exposure region of the copy material; and   shifting the strip-shaped exposure region along the copy material at a constant speed in a direction transverse to a longitudinal extent of the strip-shaped exposure region to expose image information in the original onto a total available surface of the copy material, wherein: each of said different strip-shaped portions is divided into at least two longitudinal strip-shaped sections;   separate optical representations of said sections are produced by the electro optical converter device; and   the separate optical representations of the sections are exposed in at least two longitudinal strip-shaped partial exposure regions of the copy material which form the strip-shaped exposure region.     
     
     
       2. System according to claim 1, wherein the optical representations of the sections are exposed onto the partial exposure regions by separate lenses. 
     
     
       3. System according to claim 1, wherein the optical representations of the sections of the original are sequentially produced and exposed onto the copy material. 
     
     
       4. System according to claim 1, wherein the optical representations of the sections of the original are produced locally parallel to one another and simultaneously exposed onto the copy materials. 
     
     
       5. System according to claim 1, wherein the production of the optical representations of the sections and the exposure of the optical representations onto the copy material are carried out sequentially by color. 
     
     
       6. System according to claim 1, wherein a moveable exposure optics facilitates the relative movement between the strip-shaped partial exposure regions and the copy material. 
     
     
       7. System according to claim 6, wherein the electro-optical converter device and the copy material are stationary and the partial exposure regions are moved relative to the copy material by a mirror arrangement which is moveable parallel to the copy material. 
     
     
       8. System according to claim 1, wherein the production of the optical representations of the strip-shaped sections of the original is carried out by a digital micro mirror field. 
     
     
       9. System according to claim 1, wherein the partial exposure regions overlap, and a brightness of image points depicted with the converter device within said regions are reduced to zero to compensate for a double exposure resulting from the overlap. 
     
     
       10. Apparatus for producing a photographic print of an original in electronic format by strip wise projection of image information of the original onto a photographic copy material, said apparatus comprising: a memory for the storage of said image information of the original;   an electro optical pixel wise operating converter device; and   a control associated with said electro optical converter device for producing an optical representation of strip-shaped portions of the original stored in the memory;   a projection optics for projecting the optical representations of the strip-shaped portions onto a strip-shaped exposure region of the copy material; and   drive means for shifting the strip-shaped exposure region along the copy material at a constant speed and in a direction transverse to the longitudinal extent of the strip-shaped exposure region, the control dividing each strip-shaped portion of the stored original into at least two longitudinal strip-shaped sections for producing separate optical representations by the electro optical converter device, the projection optics projecting said separate optical representations of the sections onto the copy material in at least two longitudinal strip-shaped partial exposure regions which form the strip-shaped exposure region.   
     
     
       11. Apparatus according to claim 10, wherein the projection optics includes separate lenses for the projection of the separate representations of the sections of the original in the partial exposure regions. 
     
     
       12. Apparatus according to claim 10, wherein the control associated with the electro optical converter device produces the separate optical representations of the sections sequentially and the projection optics sequentially projects the separate optical representations onto the copy material. 
     
     
       13. Apparatus according to claim 10, wherein the control associated with the electro optical converter device produces the separate optical representations of the sections of the original locally parallel to one another and the projection optics projects the separate optical representation simultaneously onto the copy material. 
     
     
       14. Apparatus according to claim 10, wherein the control associated with the electro optical converter device produces the separate optical representations of the sections of the original sequentially by color and the projection optics projects the separate optical of representations of the sections sequentially by color onto the copy material. 
     
     
       15. Apparatus according to claim 10, wherein the projection optics includes moveable components for producing the relative movement between the strip-shape partial exposure regions and the copy material. 
     
     
       16. Apparatus according to claim 15, wherein the moveable components include three redirecting mirrors, the mirrors being linearly driven parallel to the copy material and perpendicular to the longitudinal direction of the strip-shaped partial exposure regions, a first and a second of said redirecting mirrors being maintained in a fixed spatial mutual orientation for directing a projection light path by 180°,   a third redirecting mirror being positioned antiparallel to the second redirecting mirror for redirecting the light path perpendicular to the copy material, and   drive means for moving the third redirecting mirror at a speed that is twice the speed of the first and second redirecting mirrors.   
     
     
       17. Apparatus according to claim 10, wherein the electro optical converter device is a digital micro mirror field. 
     
     
       18. Apparatus according to claim 10, wherein the strip-shaped partial exposure regions positioned by the projection optics overlap and the control reduces a brightness of image points of the sections of the original projected by the converter device to zero to compensate for a double exposure resulting from the overlap.